Alana has run many marathons and keeps track of all of her finishing times. At a marathon last month, she finished in 290 minutes. The other day, she ran another marathon and finished with a time of 261 minutes. What is the percent of decrease in Alana's marathon time?

the percentage of decrease in Alana's marathon time  is 10%

Step-by-step explanation:

To start we have to know the fraction that represents what ran in the second marathon with respect to the first

to do it we have to divide the second marathon over the first

261/290 = 0.9

if we multiply this by 100 we will obtain the percentage

0.9 * 100 = 90%

if the first marathon was 100% and the second marathon was 90%

100% - 90% = 10%

the percentage of decrease in Alana's marathon time  is 10%

i think the amount would be $140.62

alright so i think for this one it would to draw it out. this may be hard for me to try and draw, but i will do my best on here:

        r

  /       |     \

notice how it forms 2 triangles inside one bigger triangle.

so if we know the angle spr is the same as psr that is saying the measure of angle p is the same as angle s. this means the big triangle psr is either isosceles or equilateral. in both cases, the triangle is perfectly symmetrical when split down the middle, which is in this case rq. because we know it is perfectly symmetrical on both sides, we know that the two triangles inside the bigger one are equal.